Effects of a 12-week intrinsic foot muscle strengthening program (STIFF) on gait, balance and concerns about falling in physically active older adults: An assessor-blinded randomized-controlled trial

Background: Falling is a major concern in the ageing population. Strengthening the plantar intrinsic foot muscles (PIFM) may improve gait and balance in older adults and, therefore, may have potential for fall prevention. Research question: The aim of the present study is to examine the effect of a PIFM strengthening program on gait, balance and functional outcomes in older adults. Methods: For this assessor-blinded RCT, older adults (> 65 years) with potentially increased fall risk were recruited at functional exercise classes and randomly assigned to an intervention (12-week supervised and progressive PIFM strengthening program) and a control group. The trial outcomes were between-group differences in mean change from baseline in maximum gait speed (primary outcome), balance during gait, foot and ankle biomechanics during gait and concerns about falling and within-group differences in capacity and strength of foot muscles. Results: Thirty-three participants were included. No between group differences were found for change in maximum gait speed. However, the intervention group showed a larger reduction in concerns about falling. In addition, the intervention group showed increased capacity and strength of foot muscles, but this was not related to other findings. Significance: This study did not show an effect of PIFM strengthening training on maximum gait speed in older adults who are involved in a functional exercise program. However, it seems to reduce concerns about falling. This advocates further research on the benefits of integrating PIFM strengthening exercises in functional exercise programs. In addition, future studies are needed to unravel the mechanism behind the reduction in concerns about falling.